Method of making perforate articles



2 Sheets-Sheet 1 ATTORNEY A. E. SIDNELL METHOD OF MAKING A PE RFORATI EARTICLE Filed May 9, 1939 B 5 5 m V A F B J 4 J Q u 7 G T n 1 Z W m n W1 Av. L 2 K 5 Eu June 9, 1942.

A. E. SIDNELL METHOD OF MAKING A PERFORATE ARTICLE June 9, 1942.

Filed May 9, 1939 2 Sheets-Sheet 2 ALBERT E.-

INVENTOR S noneu.

' ATTORNEY Patented June'9, 1942 Albert E. Sidnell, Akron, Ohio,assignor to Seiberling Latex Products Company, Barberton, Ohio,acorporation of Ohio Application May 9', 1939, Serial No. 272,586

3 Claims.

This invention relates to perforate molded articles of vulcanized rubberand in particular relates to perforate bags of elastic or resilientmaterial, such as rubber, of the type used by laundries for containingbatches-of clothes to be washed or otherwise treated, and to methods andapparatus for manufacturing the same.

Heretofore, in the manufacture of such perforate rubber laundry bags orlike articles ithas been necessary first to vulcanize the bag to shapein amold and then,v by means of expensive punching dies and heavypunching presses, to punch the perforations in the bag. Obviously, suchprocedure involved high production costs. Also, in the past the coreused in molding the bag has been made relatively thin and fiat withcurved edges of small radius extending about the same to reduce the costof the core and to reduce the weight thereof for more efllcient handlingby press operators. This produced a bag having edge portions normallycurved about a small radius and along which splitting occurred, 1 due toflexing and stretching of the bag at the edge portions when packed withclothes.

An object of the invention is to provide an improved perforate articleof the character described such as a rubber laundry bag orthe like, andto provide simple economical procedure and apparatus for producing thesame. I

Another object of th invention is to provide a substantially flatvulcanized rubber bag of the character described requiring the use of aflat and therefore light core, but having relatively large rounded edgeportions forming the curved edge portions of the bag with acomparatively large radius to obviate splitting of the bag along theseedgeswhile the bag is in service.

These and other object of the invention will be manifest from thefollowing brief description andthe accompanying drawings. Of theaccompanying drawings:

Figure 1 is a transverse cross-section, partly broken 'away, through amold as used for vulcanizing an improved laundry bag embodied in theinvention. Y

Figure 2 is an enlarged fragmentary crosssection taken on line 2-2 ofFigure 1. Figure 3 is a view showing a portion of a bag which has beenremoved from the mold after manner of mounting the bag while stillwrongside out, for removal of the nubs.

Figure 6 is an enlarged fragmentary crosssection taken on line 6-6 ofFigure 5.

Figure 7 is a plan view of a'finished bag in right-side-out condition.

Figure 8 is an enlarged cross-section taken on line 8-8 of Figure 7.

Referring to Figures 1 and 2 of the drawings,

the numeral I0 designates the lower .section, II

the upper section, and ii the intermediate seci 'tion or core of alaundry bag mold. The manner of utilizing this mold for shaping plasticsheet rubber therein to provide a laundry bag or like article iswell-known in the art.

The respective mold sections preferably are designed to formsubstantially flat bag I3 having the adjacent walls thereof relativelyclose together so as to reduce thethickness of the core, and hence theweight thereof, thereby facilitating more efflcient handling of the coreby press To prevent splitting of bag l3a1ong' the edge portions thereof,as described, the reoperators.

spective mold sections preferably are designed to form enlarged bead orrounded edge portions about the bag, as indicated at It (see Figure 1).Thus the core 82 may be of relatively thin, light weight constructionand yetforms rounded edge portions of large radius on the bag for thepurpose above referred to.

For forming perforations in the bag, the upper and .lower sections lland 52 may be provided with a plurality 'of pins [5, is which projectfrom the inner faces of said sections, the projecting ends of the pinsbeing arranged to be received in correspondingly arranged recesses l6,IS in opposite sides of core l2, when the sections are in the relationshown in Figures 1 and 2. A very slight clearance is allowed betweenpins l5 and the sides of recesses It, the clearance bestj suited for thepresent purposes having been found to be approximately .005 inch. Also,when the sections are in the press-closed positions thereof, therepreferably is allowed a substansmooth edges, as will be subsquentlydescribed.

preferably extending angularly of those on theother side, so as toproduce similarly angularly disposed ribs 2|, 2| on the inside faces ofthe bag. These ribs 2|, besides reinforcing. the bag,

.prevent the sides of th bag from sticking together.

As best shown in Figures 5 and 6, after the bag I 3 has been removedfrom the vulcanizing mold it is turned wrong-side-out to present nubs I9 to the exterior thereof and then it is stretched over a suitable fiatboard or form 22. By rubbing suitable straight edged tool or scraper orknife 23 over the surfaces of the bag to engage under nubs IS, thelatter may rapidly be separated from the bag, by virtue of the thin webl9 being easily disrupted or torn away from bag adjacent theperforations.

When the nubs l9 have been removed from both sides of the bag l3 thelatter is turned right sideout to present the reinforcing ribs H to theexterior of the bag, as shown in Figures 7 and 8.

Thus has been provided a simple, economical procedure and apparatus forproducing an improved perforate rubber article, such as the rubberlaundry bag shown and described. It is to be understood that theperforations or other openings formed in the article may be any desiredshape. For example, rectangular openings I 1, usually provided adjacentthe closure end of the bag to receive suitable closure fastening means(not shown) may be formed in the same manner as the perforations I'I.

Modifications of the invention may be resorted to without departing fromthe spirit thereof or the scope of the appended claims.

What is claimed is:

1. 'That method of making perforate bags which comprises providing acore with recesses therein where perforations are desired, forming andvulcanizing rubber or the like about the core with openings by pressingthe rubber into said recesses, the bag thus formed having projectingnubs on-the inside surface thereof pressed out of said openings andconnected to said edges of said openings by comparatively thin webs ofrubber, removing the bag from said core, turning inside out, anddisrupting said webs of rubber to remove said nubs from the surfaces ofthe bag.

2. That method of making perforate bags which comprises providing a corewith recesses therein where perforations are desired, forming andvulcanizing rubber or the like about the core with openings by pressingthe rubber into said recesses, the bag thus formed having reinforcingribs circumsoribing said openings and having projecting nubs on theinside surface thereof pressed out of said openings and connected tosaid edges of said openings by comparatively thin webs of rubber,removing the bag from said core, turning inside out, and disrupting saidwebs of rubber to remove said nubs from the surfaces of the bag.

3. That method of making perforate flexible rubber articles whichcomprises forming an article with one or more openings having one ormore hollow nubs connected thereto by thin, frangible, elastic webs ofrubber about the edges of the openings, mounting said article on asupport with said nubs extending outwardly and rubbing the outer surfaceof said article to flex and exert tension upon said frangible elasticwebs to tear the nubs free from the article.

ALBERT E. SIDNELL.

